Three‐dimensional (3D) printing processes are nowadays leading the charge in transforming traditional art, engineering, and manufacturing processes. In this study, the structural and thermal behavior of commercially available filaments composed of synthetic poly(acrylonitrile‐co‐butadiene‐co‐styrene) thermoplastic as well as poly(lactic acid) and poly(lactic acid)/polyhydroxyalcanoate reinforced with bamboo (Bambusa sp.) wood flour composite biothermoplastics were assessed by differential scanning calorimetry and infrared spectroscopy, aiming to understand the modifications that occur at the molecular level during their 3D printing. It has been determined that the biothermoplastic materials undergo both molecular reorientations related to tacticity increase and crystallinity decrease when submitted to 3D printing extrusion, while the synthetic thermoplastic undergoes crosslinking due to its butadiene component. All of the studied materials present good water stability (with water uptake values between 0.8% and 24%), and the water absorption follows a pseudo‐Fickian mechanism. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019.

The utilization of polymer-based materials is quickly expanding. The enterprises of today are progressively seeking techniques to supplant metal parts with polymer-based materials as a result of their light weight, simple support and modest costs. The ceaselessly developing requirement for composite materials with new or enhanced properties brings about the preparation of different polymer mixes with various arrangements, morphologies and properties. Fused filament fabrication processes such as 3D-printing are nowadays shaping the actual pathway to a full pallet of materials, from art–craft to biomaterials. In this study, the structural and mechanical behavior of three types of commercially available filaments comprised of synthetic poly(acrylonitrile-co-butadiene-co-styrene) (ABS), poly(lactic acid) (PLA) and poly(lactic acid)/polyhydroxyalkanoate reinforced with bamboo wood flour composite (PLA/PHA BambooFill) were assessed through mechanical testing and optical microscopy, aiming to understand how the modifications that occur in the printed models with internal architecture are influencing the mechanical properties of the 3D-printed material. It has been determined that the material printed from PLA presents the highest compression strength, three-point bending and shock resistance, while the ABS shows the best tensile strength performance. A probability plot was used to verify the normality hypothesis of data for the tensile strength, in conjunction with the Anderson–Darling statistic test. The results of the statistic indicated that the data were normally distributed and that there is a marked influence of the internal architecture of the 3D-printed models on the mechanical properties of the printed material.

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Weldability of magnesium alloy to aluminum alloy in laser weld bonded (LWB) joints are investigated. Results showed that magnesium/aluminum could be easily joined by LWB under proper technological parameters. The weld is characterized by complex vortex flow at the bottom and there existed intermetallic compound layer between weld pool and lower sheet metal which was composed of the brittle phases of Al3Mg2. The aim of this research is to evaluate the weldability using LWD process to join Mg/Al alloys using HLD 3504 – Laser Type Trumpf, to explain the experimental conditions and interpretation of results.